Abstract: A method of manufacturing curved composite structural elements can include fabricating a web ply in a flat curve over a removable substrate and laying up the ply on a curved web surface of a manufacturing tool. The method also can include laying up a diagonal ply with fibers oriented at +/?45° from the centerline of the web surface. The method further can include cutting a unidirectional composite tape into segments and laying up the tape segments to form a cross ply with a fiber orientation normal to the centerline of the web surface. One or both edges of the diagonal and cross plies may be folded over one or two sides of the manufacturing tool to form one or two flange surfaces. Additionally, a cap ply can be laid up on one or both flange surfaces using composite tape. The structural element layup can then be inspected and any excess composite material can be trimmed away.

Abstract: A vessel, such as a wing-integrated aircraft fuel tank. The vessel can include a first surface portion, a second surface portion spaced apart from the first surface portion, and a core positioned between the first and second surface portions. The core can be sealably connected to the first and second surface portions and can be positioned to carry a load from at least one of the first and second surface portions to the other. The core can include a plurality of cells separated by cell walls, at least some of which have wall openings positioned to provide liquid communication between adjacent cells.